G 


Tinting  and  Toning 

of 

Eastman  Positive 
Motion  Picture 
Film 


Price  $2.50 

Second  Edition  — Revised 


Eastman  Kodak  Company 
Rochester,  N.  Y. 

1918 


Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/tintingtoningofeOOeast 


PREFACE 


Owing  to  the  difficulty  of  obtaining  foreign  made  dyes,  a revision 
of  the  first  edition  of  this  publication  has  been  made  necessary. 

As  the  result  of  an  exhaustive  series  of  tests  of  the  products  of 
the  National  Aniline  & Chemical  Company,  Incorporated,  New  York 
City,  it  is  now  possible  to  recommend  a number  of  American  made 
dyes  suitable  for  the  tinting  of  motion  picture  film,  and  those  recom- 
mended in  this  book  are  in  most  cases  equal  in  every  respect  to  those 
previously  obtained  abroad. 

To  date,  it  has  not  been  possible  to  obtain  a thoroughly  satis- 
factory blue  dye,  film  tinted  with  the  Cine  Blue  recommended  being 
too  red,  especially  before  drying.  A more  suitable  dye  will  no  doubt 
be  available  in  due  course. 

The  number  of  sample  tints  has  been  curtailed  to  twelve,  and 
these  are  given  merely  for  guidance.  It  is  intended  that  the  various 
formulas  should  be  altered  to  suit  individual  requirements. 

The  chapter  on  toning  has  been  thoroughly  revised,  a number 
of  tones  having  been  eliminated  and  others  substituted.  The  formula 
for  the  copper  tone  has  been  improved,  while  the  formulas  for 
green  tones  requiring  the  use  of  vanadium  chloride  have  been  elim- 
inated in  view  of  the  expense  and  difficulty  of  obtaining  satisfactory 
vanadium  chloride.  With  the  samples  at  present  on  the  market  it 
has  not  been  possible  to  prepare  a single-solution  toning  bath  which 
would  keep  'for  any  reasonable  length  of  time. 

Attention  is  drawn  to  the  new  method  of  dye  toning*  recently 
worked  out  in  our  Research  Laboratory.  This  consists  in  first  treat- 
ing the  film  in  the  copper  toning  bath  and  then  immersing  the  washed 
film  in  a solution  of  a basic  dye,  the  dye  attaching  itself  to  the  image 
and  leaving  the  gelatine  clear.  Although  specific  directions  are 
given  for  obtaining  five  tones  only  by  this  method,  as  further  dyes 
are  available,  those  suitable  for  toning  purposes  will  be  published  in 
due  course. 

The  method  of  producing  sulphide  tones  has  been  changed  to  one 
of  simple  re-development  with  sodium  sulphide,  the  addition  of  hypo 
to  the  sulphide  solution  having  been  eliminated.  By  commencing 
with  thin  positive  film  of  the  correct  density,  and  using  a plain 
solution  of  sodium  sulphide  for  re-development,  satisfactory  trans- 
parent tones  are  obtainable  with  precision. 

The  formulas  for  the  iron  and  uranium  tones  are  the  same  as 
in  the  first  edition. 

EASTMAN  KODAK  COMPANY, 

August,  1918.  Rochester,  N.  Y. 

*The  patent  rights  to  this  method  are  being  secured  by  us,  but  it  may  be 
freely  used  for  toning  motion  picture  film  manufactured  by  the  Eastman 
Kodak  Company. 


Tinting  and  Toning  of  Eastman 
Positive  Motion  Picture 
Film 


TN  the  production  of  motion  picture  film  it  is  becoming  more 
**■  common  to  vary  the  color  of  the  film  either  by  toning 
or  tinting  or  by  a combination  of  the  two  processes.  Toning 
consists  in  either  wholly  or  partially  replacing  the  silver 
image  of  the  positive  film  by  some  colored  compound,  the 
clear  portions  or  highlights  of  the  image,  consisting  of  plain 
gelatine,  remaining  unaffected  and  colorless.  Tinting,  on  the 
other  hand,  consists  of  immersing  the  film  in  a solution  of 
dye  which  colors  the  gelatine  itself,  causing  the  whole  picture 
on  the  screen  to  have  a veil  of  color  over  it. 


Part  I. 


TINTING 

In  “tinting’’  the  following  factors  must  be  taken  into 
consideration : 

Nature  of  the  Dye  Employed 

Dyes  are  chemically  of  two  different  types,  acid  and 
basic ; so-called  acid  dyes  are  the  alkali  salts  of  organic 
acids,  while  basic  dyes  are  the  chlorides,  sulphates,  etc.,  of 
organic  bases. 

For  the  tinting  of  film  only  “acid”  dyes  have  been 
considered  since  it  is  not  possible  to  make  a complete  selec- 
tion from  basic  dyes  alone,  which  would  necessitate  the  use 
of  acid  and  basic  dyes  in  admixture — a procedure  highly 
undesirable  and  in  many  cases  impossible. 


5 


6 Tinting  and  Toning  of  Eastman 

Any  dye  suitable  for  admixture  with  others  to  produce 
intermediate  tints  should  possess  the  following  properties: 

A.  The  dye  should  be  inert  and  not  attack  the  gelatine 
or  support.  This  is  of  fundamental  importance  as  the 
gelatine  coating  of  dyed  film  in  many  cases  has  a tendency 
to  lose  its  flexibility,  giving  rise  to  what  is  known  in  the 
trade  as  “brittleness.” 

Several  dyes  when  employed  at  a concentration  of  1% 
attack  gelatine  readily  at  70  degrees  F.  and  vigorously  at 
80  degrees  F.,  especially  in  presence  of  small  amounts  of 
acid,  producing  a marked  softening  and  often  partial  dis- 
solution of  the  film.  The  effect  is  roughly  proportional 
to  the  concentration  of  the  dye  and  to  the  temperature,  and 
varies  with  each  individual  dye. 

Experience  has  shown  that  the  gelatine  coating  of  film 
which  has  been  softened  in  this  way  by  the  dye  becomes 
“brittle”  on  subsequent  projection. 

The  actual  factors  in  the  production  of  brittleness  are: 

1.  The  hydrolysing  action  of  acid  which  in  many  cases 
is  added  to  assist  dyeing.  In  case  a solid  acid  is  employed 
the  heat  encountered  during  projection  will  greatly  acceler- 
ate this  hydrolysis. 

2.  The  corrosive  action  of  the  dye  itself.  Dyes  vary 
considerably  in  this  respect  according  to  their  particular 
composition.  So  far,  it  has  not  been  possible  to  make 
any  general  classification  of  dyes  in  this  connection,  though 
nitro  compounds  appear  to  be  particularly  corrosive  in  their 
action. 

3.  The  presence  of  impurities  in  the  dye.  These  take 
the  form  of  excessive  amounts  of  loading  material  such 
as  sodium  sulphate  or  chloride,  or  small  traces  of  iron,  the 
latter  having  a tendency  to  harden  the  film  considerably. 

In  all  the  above  cases,  the  physical  nature  of  the  gelatine 
is  altered,  whereby  it  loses  its  property  of  remaining  resilient 
under  normal  conditions  of  temperature  and  humidity,  re- 
sulting in  “brittleness.” 

A suitable  test  as  to  whether  a dye  has  any  propensity 
to  produce  brittleness  is  to  incubate  a sample  of  film,  half 
of  which  has  been  dyed,  for  about  48  hours  at  212  degrees  F. 
If  any  difference  in  brittleness  is  noticeable  between  the 


Positive  Motion  Picture  Film 


7 


dyed  and  the  undyed  portions  so  treated  after  the  film  has 
been  allowed  to  stand  in  the  air  for  some  time,  the  dye  is 
unsuitable  for  tinting. 

Apart  from  the  above,  most  dyes  when  used  at  a con- 
centration of  1%  and  at  80  degrees  F.  produce  more  or 
less  softening  of  the  gelatine,  which  may  be  prevented  by : 

(a)  Use  of  only  dilute  solutions.  Except  in  very 
special  cases,  a dye  solution  stronger  than  0.5%  is  seldom 
required,  the  usual  strength  employed  being  about  0.2%,  at 
which  concentration  softening  is  unusual. 

(b)  Use  of  a minimum  amount  of  volatile  acid  in  the 
dye-bath  or  omission  of  the  same  whenever  possible. 

(c)  By  working  at  temperatures  not  higher  than  70 
degrees  F. 

(d)  By  slight  hardening  of  the  film  before  dyeing  and 
subsequent  softening  by  glycerine,  as  described  below: 

B.  The  dye  should  not  “bleed”  to  any  considerable 
extent  when  the  film  is  washed ; in  other  words,  the  rate 
of  removal  of  the  dye  should  be  slow  and  only  a slight 
amount  should  wash  out  in  a period  of,  say,  five  minutes. 

In  tinting,  bleeding  is  of  very  considerable  importance, 
since,  during  the  periods  between  rinsing  after  dyeing  and 
the  placing  of  the  film  on  the  drying  rack,  any  drops  of 
water  on  the  surface  of  the  film  become  more  or  less 
saturated  with  dye,  and  these  after  drying  remain  as  spots 
and  irregular  markings  which  are  very  apparent  on  the 
screen. 

It  is  possible  in  some  cases  to  modify  this  bleeding  by  an 
acid  “stop  bath,”  or  by  adding  acid  to  the  dye-bath ; though 
it  may  be  considered  a general  rule  that  the  bleeding  of  a dye 
is  a property  peculiar  to  itself.  In  making  a selection  of 
dyes  therefore,  it  is  necessary  to  choose  only  those  whose 
propensity  for  bleeding  is  a minimum. 

C.  The  rate  of  dyeing  should  be  only  slightly  affected 
by  the  addition  of  acid  to  the  dye-bath,  although  most  acid 
dyes  are  more  or  less  sensitive  to  acid. 

In  case  the  rate  of  dyeing  is  appreciably  affected  by  the 
addition  of  acid  it  is  possible  to  take  advantage  of  this  fact 
since  a much  weaker  dye  solution  may  be  employed  to 
obtain  a given  tint,  while  an  apparently  exhausted  bath  may 
be  revived  by  adding  a small  trace  of  acid. 


8 


Tinting  and  Toning  of  Eastman 


Only  a volatile  acid  such  as  acetic  acid  should  be  used 
since  this  will  evaporate  on  drying,  while  the  strength  of 
the  acid  in  the  dye-bath  should  not  exceed  .05%  or  one 
part  in  2000,  otherwise  softening  of  the  gelatine  is  liable 
to  occur,  especially  if  the  temperature  exceeds  70°  F. 

In  the  case  of  a bath  containing  a mixture  of  dyes,  owing 
to  the  fact  that  acid  affects  some  dyes  more  than  others,  as 
the  dye-bath  becomes  exhausted  and  the  acid  content 
changes,  the  tint  obtained  will  gradually  change  also.  It  is 
only  possible  therefore  to  use  acid  with  any  degree  of  cer- 
tainty in  the  case  of  dye-baths  containing  a single  dye. 

D.  The  dyes  should  not  fade  on  exposure  to  heat  or 
light  and  should  not  be  “dichroic”  or  change  color  on 
dilution. 

Moreover,  the  wear  and  tear  of  the  film  should  not  be 
impaired  in  any  way  after  dyeing,  and  even  after  incubating 
for  48  hours  at  212  degrees  F.,  afterwards  allowing  the  film 
to  humidify,  no  difference  should  be  discernible  between 
dyed  and  undyed  film  so  treated. 

E.  The  dye  should  not  be  affected  by  the  acid  fixing 
bath  since  any  fixing  solution  accidentally  splashed  thereon, 
would  destroy  the  dye  immediately. 

In  view  of  the  large  number  of  tints  required  in  com- 
mercial work,  it  is  undesirable  to  keep  a separate  dye-powder 
for  the  preparation  of  each  particular  bath,  but  rather  to 
prepare  the  same  by  admixture  of  three  or  more  dyes.  If 
three  only  are  employed,  mixing  must  be  conducted  with 
great  precision  in  order  to  reproduce  any  given  tint,  but  this 
difficulty  is  removed  by  the  use  of  intermediate  colors. 

The  following  six  standard  dyes  have  been  chosen  as 
fulfilling  the  above  conditions  as  nearly  as  possible,  and  by 
suitably  mixing  solutions  of  these,  almost  any  desired  tint 
may  be  obtained. 

Name  Used  in  Formula  Commercial  Name 

Cine  Red  Serichrome  Blue  R 


“ Scarlet 
“ Orange 
“ Yellow 
“ Green 
“ Blue 


Orange  A Concentrated 
Niagara  Fast  Yellow 
Ammaco  Acid  Green  L 
Buffalo  Fast  Blue  R 


Crocein  Scarlet  MOO 


Positive  Motion  Picture  Film 


9 


These  dyes  are  obtainable  from  the  National  Aniline  & 
Chemical  Co.,  Inc.,  New  York  City. 

The  strength  of  the  dyes  may  vary  slightly  from  batch 
to  batch,  but  this  variation  is  usually  so  small  as  not  to 
materially  affect  the  nature  of  the  tint  obtained  from  any 
particular  formula. 

The  Cine  Blue  dye  appears  much  redder  by  artificial 
light  than  by  daylight,  especially  before  drying  the  film,  as 
do  all  tints  containing  Cine  Blue. 

The  following  formulas  are  given  merely  for  guidance 
and  should  be  altered  to  suit  individual  requirements. 

When  matching  any  color  view  only  by  artificial  light. 


Formulas  for  Tinting  at  65°  F. 


Tint  Number  on  Chart 

Avoirdupois 

Metric 

Time  of  Tinting 

1.  Cine  Red 

Acetic  Acid  (Glacial) 
Water 

8 ozs. 
3^4  ozs. 
50  gals. 

250  grams 
100  grams 
200  liters 

5 minutes 

2.  Cine  Red 
Water 

8 ozs. 
50  gals. 

250  grams 
200  liters 

10  minutes 

3.  Cine  Scarlet 

Acetic  Acid  (Glacial) 
Water 

8 ozs. 
V/2.  ozs. 
50  gals. 

250  grams 
100  grams 
200  liters 

5 minutes 

4.  Cine  Orange 

Acetic  Acid  (Glacial) 
Water 

8 ozs. 
3K  ozs. 
50  gals. 

250  grams 
100  grams 
200  liters 

4 minutes 

5.  Cine  Orange 
Water 

1 lb. 

50  gals. 

500  grams 
200  liters 

10  minutes 

6.  Cine  Yellow 
Water 

8 ozs. 
50  gals. 

250  grams 
200  liters 

10  minutes 

7.  Cine  Yellow 
Cine  Green 
Water 

4 ozs. 
8 ozs. 
50  gals. 

125  grams 
250  grams 
200  liters 

10  minutes 

8.  Cine  Green 
Water 

13  ozs. 
50  gals. 

400  grams 
200  liters 

10  minutes 

9.  Cine  Green 
Cine  Blue 
Water 

8 ozs. 
8 ozs. 
50  gals. 

250  grams 
250  grams 
200  liters 

10  minutes 

10.  Cine  Blue 
Water 

8 ozs. 
50  gals. 

250  grams 
200  liters 

10  minutes 

11.  Cine  Blue 
Water 

4 ozs. 
50  gals. 

125  grams 
200  liters 

10  minutes 

12.  Cine  Blue 
Cine  Red 
Water 

8 ozs. 
4 ozs. 
50  gals. 

250  grams 
125  grams 
200  liters 

10  minutes 

10 


Tinting  and  Toning  of  Eastman 


Method  of  Mixing 

Dissolve  the  solid  dyes  in  as  small  an  amount  of  hot 
water  as  possible,  and  filter  through  fine  muslin.  Pour  hot 
water  over  any  residue  remaining,  which  should  only  be 
slight,  in  order  to  ensure  thorough  solution  of  the  dye,  and 
dilute  the  solution  in  the  tank  to  the  required  volume  at  65 
degrees  F. 

Nature  of  Positive  Film 

Only  good  snappy  positive  film  may  be  successfully 
tinted,  since  tinting  tends  to  reduce  contrast. 

The  depth  of  the  tint  obtained  depends  on  the  following 
factors : 

Nature  and  Strength  of  the  Dyebath 

Except  in  special  cases  such  as  fire  scenes,  sunset  and 
moonlight  effects,  and  the  like,  it  is  very  undesirable  to 
employ  strong  tints,  since  apart  from  the  displeasing  effect 
and  irritation  to  the  eye,  the  dyes  produce  a slight  soft- 
ening of  the  gelatine  film  when  used  at  80  degrees  F.  in 
1%  solution. 

Should  it  be  necessary  to  employ  concentrated  baths  in 
summer,  either  cool  the  dye-bath  or  use  a suitable  hardener. 
This  will  be  unnecessary  if  hardener  is  employed  in  the 
fixing  bath  after  development,  but  otherwise  if  formalin 
(40%)  be  added  to  the  dye-bath  to  the  extent  of  1 volume 
to  400  volumes  of  dye  solution,  no  trouble  will  be  encoun- 
tered. During  the  winter  months,  when  it  is  advisable  to 
treat  all  film  after  developing  and  fixing,  with  glycerine, 
the  latter  may  be  incorporated  with  the  dye-bath,  thereby 
eliminating  an  extra  operation.  The  strength  of  the 
glycerine  should  be  2%,  or  two  volumes  per  one  hundred 
volumes  of  dye  solution.  In  most  cases,  however,  the  addi- 
tion of  glycerine  considerably  retards  the  rate  of  dyeing,  so 
that  in  order  to  obtain  the  same  degree  of  tinting  within  a 
period  of  ten  minutes,  the  concentration  of  the  dye-bath 
should  be  increased  accordingly. 

When  delicate  tints  are  employed,  the  effect  is  both  to 
remove  the  contrasty  black  and  white  effect,  and  to  add  a 
touch  of  warmth  to  the  black  deposit  of  silver,  even  in  cases 
where  the  highlights  are  insufficiently  stained  to  be  notice- 
able. The  result  in  many  cases  is  equal  to  that  obtained 
by  partial  toning,  for  example,  tint  No.  11  gives  the  effect 
of  a blue-black  tone. 


Positive  Motion  Picture  Film 


11 


Temperature  of  Dye-bath 

Although  temperature  has  little  effect  on  the  rate  of 
dyeing  with  the  dyes  recommended,  when  used  without  the 
addition  of  acid  it  is  advisable  in  all  cases  to  work  at  65  to 
| 70  degrees  F.  in  order  to  produce  uniform  results  and  re- 
move any  danger  of  softening  the  film. 


Time  of  Dyeing 

In  order  to  duplicate  any  particular  tint  with  a given 
dye-bath  the  film  may  be  dyed  either  by  time  or  by  inspection. 
Dyeing  by  time  is  reliable  if  the  dye-bath  does  not  contain 
acid,  though  if  acid  is  present,  in  time  the  acidity  decreases, 
causing  a slowing  down  of  the  rate  of  dyeing  so  that  it 
becomes  necessary  to  judge  the  progress  of  dyeing  by 
J inspection. 

If  two  or  more  tints  of  the  same  color  are  required,  in 
order  to  reduce  the  number  of  individual  dye-baths  to  a 
minimum,  it  is  better  to  vary  the  time  of  dyeing  rather  than 
to  vary  the  dilution  of  the  bath,  providing  the  time  of  dye- 
ing for  the  lighter  tint  is  not  less  than  one  minute,  which 
time  is  considered  a minimum  for  the  production  of  uniform 
results  and  for  complete  control  of  the  dyeing  operations. 

The  time  of  dyeing  also  depends  somewhat  on  the  previ- 
ous handling  of  the  film.  Film  which  has  been  fixed  in  a 
bath  containing  ordinary,  or  chrome  alum,  dyes  more 
quickly  than  that  treated  with  plain  hypo  and  hardened  with 
formalin. 

It  is  probable  therefore,  that  small  traces  of  alum  are 
left  in  the  film  even  after  prolonged  washing,  which  serve 
as  a mordant  for  the  dye. 

The  film  samples  herewith  shown  were  fixed  in  the 
regular  acid  hypo  bath,  so  that  if  for  any  reason  the  tints 
indicated  are  not  obtained  in  the  time  stated,  then  either 
the  time  of  dyeing  or  the  dilution  of  the  dyebath  should  be 
altered  accordingly. 

Should  the  film  for  any  reason  be  over-dyed,  a small 
portion  of  the  dye  may  be  removed  by  washing  for  10  to  15 
minutes,  though  the  nature  of  the  dyes  will  permit  only 
slight  mistakes  to  be  rectified  in  this  manner. 


12 


Tinting  and  Toning  of  Eastman 


Life  of  the  Dye-baths 

This  averages  about  40,000  feet  per  50  gallons  of  dye- 
bath.  The  baths  may  be  revived  at  intervals  by  the  addition 
of  more  dye,  though  this  procedure  is  uncertain  and  it  is 
generally  advisable  to  mix  fresh  solution. 

The  addition  of  a trace  of  acetic  acid  (1  part  in  1000) 
will  revive  an  apparently  exhausted  bath  though  as  stated 
above,  it  is  only  advisable  to  do  this  in  the  case  of  baths 
containing  a single  dye. 

Method  of  Procedure 

Either  the  “drum”  or  “rack”  method  may  be  employed, 
and  in  either  case  after  dyeing  for  ten  minutes  (during  which 
time  the  drum  or  rack  should  be  agitated  to  ensure  even 
dyeing  and  prevent  accumulation  of  air  bubbles)  the  film 
should  be  given  a thorough  rinse  in  plain  water. 

Before  drying  films  on  racks  it  is  advisable  to  set  the 
rack  at  a slight  angle  for  a few  minutes,  to  enable  the  surplus 
water  to  drain  off  more  readily  through  the  perforations. 
If  drums  are  used  for  drying  it  is  advisable  to  remove  the 
surplus  water  by  whirling  the  drum  previous  to  drying. 

If  uniform  results  are  to  be  obtained,  film  should  never 
be  passed  through  the  projector  before  either  tinting  or 
toning. 


How  to  Obtain  Intermediate  Tints 

The  twelve  tints  above  are  given  merely  as  examples ; 
other  tints  may  be  readily  obtained  by  making  a trial  with  a 
small  amount  of  solution  on  a short  length  of  film,  taking 
care  to  match  the  tint  in  artificial  light  and  not  by  daylight, 
since  any  dye  containing  Cine  Blue  appears  redder  by  arti- 
ficial light  than  by  daylight. 

When  matching  think  of  the  tint  as  being  made  up  of 
one  or  more  of  the  colors,  red,  yellow,  and  blue.  Colors 
such  as  orange  are  made  by  mixing  yellow  and  red,  violet 
by  mixing  red  and  blue,  and  green  by  mixing  yellow  and 
blue.  Browns  are  obtained  by  mixing  all  three  colors  red, 
yellow,  and  blue. 


Positive  Motion  Picture  Film 


13 


When  comparing  any  two  particular  tints,  it  is  usual  to 
say  that  one  is  redder,  yellower  or  bluer  than  the  other,  and 
the  two  may  therefore  be  matched  accordingly. 

Choice  of  Tint 

Almost  any  tint  if  delicate  may  be  employed  with  ad- 
[ vantage,  though  for  general  use  those  ranging  through  pink, 
rose,  orange,  yellow,  pale  green  and  pale  blue  are  to  be 
| recommended;  others  are  for  special  purposes. 

It  is  always  desirable  to  obtain  harmony  in  color, 
especially  when  combining  tinting  with  toning,  so  that  the 
. combination  is  pleasing  to  the  normal  eye. 

For  local  tinting  and  hand  coloring,  the  above  dyes  are 
likewise  satisfactory. 


Troubles  in  Tinting 

Streaks  and  Uneven  Coloring 

Cause 

a.  Grease  on  the  film.  Never  project  film  before  tinting. 

b.  Slight  bleeding  and  insufficient  squeegeeing  when  on 
the  drying  rack.  Always  carefully  remove  any  surface 
moisture  from  the  film  with  a damp  chamois,  before  drying. 


Sludge  in  the  Dye-bath 

This  is  due  to  the  precipitation  of  the  dye  by  small  traces 
of  alum  or  iron  in  the  water  supply.  In  many  localities 
water  is  purified  by  adding  alum,  and  only  the  smallest  trace 
need  be  present  to  throw  some  of  the  dye  out  of  solution. 

Frothing  of  the  Dye-bath 

This  occurs  only  when  tinting  on  the  drum  with  Cine 
Scarlet,  Cine  Orange,  and  Cine  Green,  but  no  inconvenience 
will  be  caused  if  the  drum  is  revolved  slowly. 


Part  II. 


TONING 

As  distinct  from  tinting,  a toned  image  consists  of  a 
color  image  embedded  within  a layer  of  colorless  gelatine, 
so  that  while  the  highlights  are  clear,  the  shadows  are 
colored. 

The  coloring  matter  may  consist  of  an  inorganic  colored 
compound  or  a dye,  or  of  a mixture  of  both,  and  by  wholly 
or  partially  replacing  the  black  and  white  silver  image  by 
one  or  more  of  these  substances,  a colored  image  is  produced. 

It  is,  of  course,  important  that  the  colored  compound 
should  be  as  transparent  as  possible  so  that  the  full  tone 
will  be  apparent  on  projection.  In  this  respect,  while  some 
samples  of  toned  film  appear  colored  in  the  hand,  they  pro- 
duce a substantially  black  and  white  image  on  projection,  so 
that  when  judging  any  particular  tone,  it  is  absolutely  neces- 
sary to  view  the  image  on  the  screen. 

Of  the  various  inorganic  colored  compounds,  the  metallic 
ferrocyanides  are  the  most  suitable  for  toning  purposes  of 
which : 

Iron  (ferric)  ferrocyanide  is  blue, 

Copper  ferrocyanide  is  red,  and 
Uranium  ferrocyanide  is  reddish  brown. 

It  is  the  object  in  toning  to  replace  the  metallic  silver 
composing  the  image  more  or  less  by  one  of  the  above 
compounds  or  by  a mixture  of  these.  In  this  way  inter- 
mediate tones  are  obtained. 

Toning  may  be  effected  either  by  a single  solution  process 
or  a two  solution  process. 

Two  Solution  Process 

This  consists  of  first  converting  the  silver  image  into 
silver  ferrocyanide  by  a suitable  bleaching  bath,  thoroughly 
washing,  and  acting  upon  the  ferrocyanide  image  with  a 
metallic  salt,  usually  in  presence  of  an  acid,  the  metallic 


15 


16 


Tinting  and  Toning  of  Eastman 


ferrocvanide  being  produced  by  double  decomposition.  The 
reaction,  however,  is  never  complete,  so  that  the  image  is 
mixed  with  undecomposed  silver  ferrocyanide  which  tends 
to  make  the  image  opaque,  but  at  the  same  time  it  also  adds 
“body”  to  the  latter.  Providing  allowance  is  made  in  the 
original  positive  for  this  intensification,  good  tones  are 
obtained.  (See  Tone  G.) 

Single  Solution  Process 

Instead  of  the  two  separate  baths  used  above,  a single 
solution  may  be  employed  consisting  of  a metallic  ferri- 
cyanide  dissolved  in  a suitable  solvent  (say,  an  alkali  salt 
of  citric,  tartaric,  or  oxalic  acids)  in  presence  of  an  acid 
and  certain  other  salts. 

On  immersion  of  the  positive  film  in  this  solution  the 
silver  image  is  converted  to  silver  ferrocyanide,  while  the 
colored  ferrocyanide  is  formed  simultaneously  and  combined 
with  it. 

In  either  of  the  above  cases  in  view  of  the  fact  that  the 
metallic  ferrocyanide  is  deposited  in  a colloidal  condition  in 
presence  of  the  gelatine  of  the  film,  its  state  of  division  and 
the  nature  of  the  tone  are  usually  affected  by  the  presence 
of  certain  salts,  changes  of  temperature,  concentration  of 
the  baths  and  other  factors  which  must  be  maintained  con- 
stant in  order  to  obtain  uniform  results.  With  such  single 
baths  it  is  possible  to  secure  tones  which  are  unobtainable 
by  a two  solution  process,  though  as  such  single  solutions  are 
sensitive  to  light  and  rapidly  attack  foreign  metals  which 
may  be  present  in  the  shape  of  faucets,  etc.,  such  solutions 
are  comparatively  unstable  and  require  care  in  their  use. 

Dye  Toning 

Owing  to  the  limited  number  of  colored  inorganic  com- 
pounds available  for  toning  purposes,  it  is  possible  to  obtain 
only  a limited  range  of  tones  by  the  above  methods. 

In  view  of  the  possible  wide  range  of  colors  obtainable 
by  the  use  of  dyes,  it  has  long  been  considered  that  a 
satisfactory  method  of  producing  a dye  image  would  be  the 
ideal  method  for  toning  purposes. 

As  a result  of  recent  work  in  our  Research  Laboratory, 
it  is  now  possible  to  recommend  such  a method  of  toning 
which  depends  upon  the  fact  that  certain  inorganic  com- 
pounds, including  copper  ferrocyanide,  have  the  property 


Positive  Motion  Picture  Film 


17 


of  mordanting  certain  basic  dyes,  so  that  when  they  are 
immersed  in  a solution  of  the  dye  the  latter  attaches  itself 
to  the  mordant,  which  in  turn  becomes  colored. 

The  most  suitable  dyes  for  dye  toning  are  those  which 
do  not  readily  dye  gelatine  so  that  on  immersing,  say,  a 
sample  of  copper  toned  film  in  a weak  solution  of  the  dye 
i containing  a little  acid,  the  dye  becomes  mordanted  to  the 
image,  while  the  high-lights  consisting  of  clear  gelatine  re- 
main colorless,  the  resulting  tone  being  a combination  of  the 
[ color  of  the  toned  film  and  the  dye. 

Full  particulars  are  given  under  tones  J,  K,  L,  M and  N. 


Nature  of  the  Positive  to  be  Toned 

Since  most  toning  processes  either  intensify  or  reduce  the 
original  image,  in  order  to  obtain  uniform  results,  commence 
toning  with  positive  film  of  the  correct  density. 

Three  standards  of  positive  film  have  been  chosen : Thin, 
Medium  and  Normal.  (See  chart.)  The  “Thin”  and 
“Medium”  standards  are  obtained  by  giving  a slight  over- 
exposure and  a shorter  time  of  development. 

The  exact  degree  of  intensification  which  takes  place 
in  any  particular  case  will  soon  be  learned  after  a few  trials. 

Nature  of  the  Developer 

Any  good  Elon-Hydrochinon,  Kodelon-Hydrochinon,  or 
straight  Hydrochinon  formula  will  give  satisfactory  tones, 
though  in  the  case  of  Tone  G an  Elon-Hydrochinon  devel- 
oper is  essential  in  order  that  a rich  olive  color  may  be 
obtained. 

For  toning,  it  is  necessary  that  the  developed  film  should 
be  entirely  free  from  fog,  since  a thin  veil  becomes  intensi- 
fied in  most  of  the  toning  processes.  Fog  may  be  caused  by : 

(a)  Oxidation  of  the  developer,  noticeable  by  the  brown 
coloration  produced  after  continued  use.  The  remedy  is  to 
renew  the  developer. 

(b)  Carelessness  in  compounding  the  developer.  The 
usual  mistake  consists  in  adding  the  carbonate  to  the  Elon 
and  Hydrochinon  without  previously  adding  a portion  of 
sulphite  to  prevent  oxidation.  It  is  not  advisable,  however, 
to  add  the  whole  of  the  sulphite  to  the  Elon  and  Hydro- 
chinon in  the  first  place,  otherwise  the  Elon  may  precipitate. 


18  Tinting  and  Toning  of  Eastman 

Mixing  the  developer  with  water  which  is  too  warm  will 
often  cause  fog. 

(c)  The  presence  of  copper,  brass,  and  tin,  the  fumes 
from  sodium  sulphide,  etc.,  in  the  developing  baths  are  to  be 
strictly  avoided.  A salt  of  copper  if  present  only  to  the 
extent  of  one  part  in  10,000  will  produce  fog  on  cine  positive 
film. 

Fixing 

This  operation  should  be  complete  and,  if  possible, 
carried  out  in  two  consecutive  baths  and  followed  by  thor- 
ough washing,  otherwise  uneven  coloring  will  result. 

In  order  to  eliminate  any  possibility  of  uneven  toning  it 
is  always  advisable  to  tone  immediately  after  washing  and 
before  drying. 

Control  in  Toning 

As  in  the  case  of  tinting,  the  nature  of  the  tone  obtained 
with  the  various  solutions  depends  on  the  following  factors : 

a.  The  nature  and  dilution  of  the  toning  solutions. 
Except  in  those  cases  where  it  is  recommended  to  revive  the 
bath  by  adding  more  acid,  it  is  not  advisable  to  modify 
the  composition  or  dilution  of  the  various  solutions,  as  these 
have  been  adjusted  to  give  the  best  results. 

b.  Temperature  of  toning. 

In  most  cases  a change  of  temperature  from  60  to  70 
degrees  F.  has  merely  the  effect  of  changing  the  time  of 
toning.  It  is  advisable,  however,  to  maintain  the  tempera- 
ture of  the  various  solutions  between  65  degrees  and  70 
degrees  F. 

c.  Time  of  toning. 

Except  in  the  case  of  tones  F and  G when  toning 
proceeds  to  a limit,  the  nature  of  the  tone  produced  varies 
with  the  time  of  toning,  reaching  a limit  in  from  10  to  15 
minutes,  so  that  in  a shorter  time  intermediate  tones  are 
produced.  Since  most  of  the  toning  processes  intensify  the 
original  image,  if  an  intermediate  tone  is  required,  it  is 
usually  necessary  to  commence  toning  with  denser  film  than 
when  toning  is  to  be  carried  to  the  limit.  See  tones  B,  C 
and  D. 

When  producing  intermediate  tones,  it  is  therefore 
possible  either  to  tone  in  the  normal  bath  for  a given  time 


Positive  Motion  Picture  Film 


19 


or  in  a diluted  bath  for  a longer  time.  In  order  to  reduce 
the  number  of  individual  toning  baths  to  a minimum  it  is 
recommended  to  vary  the  time  of  toning  rather  than  to  vary 
the  dilution  of  the  bath  and  to  judge  the  tone  by  inspection. 
Since  the  strength  of  the  toning  bath  falls  off  with  use, 
inspection  is  necessary  in  all  cases  except  Tones  F and  G. 

Before  commencing  work  with  any  bath,  it  is  advisable 
to  make  a test  on  a short  length  of  film. 

Permanency  of  Tones 

The  permanency  of  the  tones  produced  largely  depends 
on  the  care  exercised  throughout  the  various  operations. 

The  silver  sulphide  image  may  be  considered  permanent, 
though  in  the  other  cases,  where  more  or  less  silver  ferro- 
cyanide  is  present,  the  toned  image  is  not  absolutely  perma- 
nent, being  somewhat  soluble  in  hypo  and  affected  by  fumes 
of  sulphuretted  hydrogen. 

In  the  case  of  the  iron  and  uranium  tones,  the  colored 
ferrocyanides  are  dissolved  by  alkali  such  as  sodium  car- 
bonate, so  that  the  toned  film  should  not  be  washed  for  too 
long  a time  in  water  which  is  at  all  inclined  to  be  alkaline. 

In  no  case  however,  if  the  instructions  are  carefully 
followed  will  the  toned  image  deteriorate  during  the  active 
life  of  the  film.  Moreover,  so  far  as  can  be  ascertained, 
the  wear  and  tear  of  film  which  has  been  toned  by  the 
methods  recommended  is  in  no  way  impaired,  though  by 
virtue  of  the  hardening  action  of  most  of  the  toning  baths 
on  the  gelatine  it  is  advisable,  especially  during  the  winter 
months,  to  immerse  the  film  for  three  or  four  minutes  in 
the  usual  2%  glycerine  bath  after  toning. 

Should  film  have  to  be  stored  for  long  periods  of  time, 
toning  is  inadvisable,  nor  is  it  advisable  to  tone  valuable 
film  unless  duplicates  are  available. 

The  life  of  the  toning  bath  has  been  carefully  investigated 
in  each  case,  the  term  “life”  being  considered  as  the  total 
length  of  film  capable  of  being  toned  by  a given  volume 
of  fresh  solution  when  toning  is  conducted  continuously 
and  without  interruption. 

In  all  cases  it  is  false  economy  to  exhaust  a toning  bath 
to  the  limit  and  thus  obtain  inferior  tones,  since  the  cost  of 
the  chemicals  employed  is  insignificant  compared  with  the 
value  of  the  film  being  treated. 

Since  the  figures  given  represent  the  capacity  of  the  bath 


20  Tinting  and  Toning  of  Eastman 

for  toning  under  the  best  conditions,  they  only  apply  pro- 
viding the  baths  are  kept  covered  as  far  as  possible  when 
not  in  use,  to  exclude  light,  and  providing  no  foreign 
metallic  surface,  however  small,  is  allowed  to  come  into 
contact  with  the  solution. 

As  mentioned  above,  single  solution  baths  are  not  in- 
tended for  occasional  use.  In  such  cases  two-solution 
methods  should  as  far  as  possible  be  employed,  although  it 
has  only  been  possible  to  recommend  the  latter  for  the 
production  of  sulphide  and  blue-green  tones. 

Stability  of  the  Solutions 

All  toning  solutions  containing  potassium  ferricyanide 
are  sensitive  to  light,  the  ferricyanide  being  reduced  to  fer- 
rocyanide.  Therefore  when  not  in  use  the  tanks  should  be 
carefully  covered  so  as  to  screen  the  solutions  from  sunlight. 

It  is  also  very  important  that  no  metallic  surface  how- 
ever small  should  come  in  contact  with  the  solutions ; any 
metal  pegs  on  the  racks  or  pins  used  to  hold  the  film  together 
will  gather  the  tone  in  preference  to  the  film,  causing  the 
formation  of  sludge.  Plain  wooden  racks  with  or  without 
wooden  pegs  should  be  used,  and  metal  faucets  replaced  by 
wooden  plugs. 

If  any  considerable  amount  of  sludge  forms  in  the  tank 
at  any  time,  it  is  due  either  to  incorrect  mixing,  the  action 
of  light,  or  to  the  presence  of  foreign  metallic  substances. 

Tone  A 

Tone  A Red  (Copper) 

Positive  Employed — Normal 

After  immersion  of  the  well  washed  film  in  water  for  one 


minute,  bathe  in  the  following: 

Avoirdupois  Metric 

Copper  sulphate  1 lb.  11  ozs.  800  grams 

Ammonium  citrate  (neutral)  5 lbs.  3 ozs.  2500  “ 

Potassium  ferricyanide  1 lb.  11  ozs.  800  “ 

Ammonium  carbonate  13  ozs.  400  “ 

Water  to  50  gals.  200  liters 


Dissolve  each  ingredient  separately  in  as  little  water  as 
possible,  mix  the  filtered  solutions  so  obtained  in  the  order 
given,  and  dilute  to  the  required  volume.  The  solution  ob- 
tained should  be  light  green  in  color  and  perfectly  clear. 
The  ammonium  carbonate  should  be  almost  transparent  and 
free  from  white  powder,  and  should  be  dissolved  in  cold 


Positive  Motion  Picture  Film 


21 


water,  while  the  ammonium  citrate  employed  should  be 
neutral.  Most  samples  contain  acid,  which  acid  would 
neutralize  the  ammonium  carbonate  and  affect  the  resulting 
tone.  The  free  acid  is  usually  citric  acid,  and  should  be 
neutralized  with  a solution  of  ammonia  using  litmus  as 
indicator. 

Temperature  of  Toning — To  obtain  the  best  results  the 
temperature  of  the  bath  should  be  from  65  degrees  to  70 
degrees  F. 

Time  of  Toning — Five  to  ten  minutes. 

Time  of  Washing — 10  minutes. 

Life  of  Bath — With  use  the  bath  precipitates  a brown 
sludge  of  copper  ferrocyanide,  and  in  consequence  becomes 
weaker  by  virtue  of  the  loss  of  copper,  though  50  gallons  of 
the  solution  will  tone  about  10,000  feet  of  film. 

It  is  necessary  to  keep  the  film  entirely  submerged  in 
the  tank,  or  constantly  in  motion  when  on  the  drum,  other- 
wise if  the  film  is  frequently  examined,  especially  during  the 
first  few  minutes  of  toning,  streaks  are  liable  to  occur. 


Tone  B 


Tone  B Red  (Uranium) 
Positive  Employed — Thin. 


Immerse  the  well  washed  film  in  the  following: 


Uranium  Nitrate  (Neutral) 

Potassium  Oxalate  (Neutral) 

Potassium  Ferricyanide 
Ammonium  Alum 
Hydrochloric  Acid  10% 

Water  to 

Mix  in  the  order  given.  The  solution  obtained  should  be 
perfectly  clear  and  pale  yellow  in  color. 

In  view  of  the  fact  that  the  nature  of  the  tone  is  in- 


Avoirdupois 
16^  ozs. 

1 6x/2  ozs. 
6J4  ozs. 
2^  lbs. 

1 quart 
50  gals. 


Metric 
500  grams 
500  grams 
200  grams 
1200  grams 
1000  cc. 

200  liters 


fluenced  largely  by  the  acid  content,  it  is  very  important 
that  the  uranium  nitrate  should  contain  no  free  acid,  and 
this  may  be  assured  by  neutralizing  a solution  with  dilute 
ammonia  until  a slight  permanent  precipitate  is  obtained. 

It  is  convenient  to  keep  stock  solutions  of  the  above 
(say,  10%  solutions)  from  which  a new  bath  may  be 
expeditiously  compounded.  A 10%  hydrochloric  acid  solu- 
tion is  one  containing  10  parts  by  volume  of  the  concentrated 
acid  per  100  volumes  of  the  final  solution. 


22 


Tinting  and  Toning  of  Eastman 


Temperature  of  Toning — 65  degrees  to  70  degrees  F. 

Time  of  Toning — Ten  minutes. 

Since  this  and  the  following  single  solution  methods  of 
toning  produce  a marked  intensification  of  the  silver  image — 
which  intensification  increases  with  the  time  of  toning — it 
follows  that  the  nature  of  the  tone  changes  with  time  also. 

The  composition  of  the  bath  has  been  so  adjusted  that 
the  maximum  effect  is  produced  in  about  10  minutes,  the 
tone  passing  through  a series  of  changes  from  brown  to 
red  during  this  time. 

It  is  therefore  possible  to  obtain  intermediate  tones  by 
withdrawing  the  film  from  the  bath  at  shorter  intervals, 
though  in  such  cases  the  contrast  of  the  original  black  and 
white  film  should  be  adjusted  accordingly,  since  with  slight 
toning  very  little  intensification  takes  place.  (See  tones 
C and  D.) 

Time  of  Washing — Ten  to  fifteen  minutes. 

The  highlights  will  become  clear  in  the  above  time, 
though  a thin  yellowish  brown  veil  may  remain  in  the  clear 
gelatine  as  a result  of  the  intensification  of  minute  traces 
of  fog,  but  this  has  no  effect  on  projection.  If  the  bath  is 
working  correctly  the  yellowish  veil  is  only  just  perceptible, 
but  if  appreciably  visible,  then  either  the  film  was  fogged 
during  development,  or  the  bath  was  not  compounded  cor- 
rectly. Washing  should  not  be  carried  out  for  too  long  a 
period,  especially  with  water  inclined  to  be  alkaline,  because 
the  toned  image  is  soluble  in  alkali. 

Life  of  Bath 

Fifty  gallons  of  solution  will  tone  about  5000  feet  of 
film  without  any  appreciable  change  in  the  tone,  after  which 
the  rich  tone  tends  to  flatness  as  a result  of  a deficiency 
of  acid  in  the  bath.  At  this  point  the  bath  may  be  revived 
by  the  further  addition  of  acid  to  the  extent  of  the  original 
amount,  when  a further  5000  feet  may  be  toned.  At  this 
stage  the  richness  of  tone  falls  off  rapidly  and  the  bath 
should  be  thrown  away. 

Used  intermittently  over  a period  of  several  days  the 
life  of  the  bath  is  approximately  the  same. 

With  continued  use  a slight  brownish  flocculent  precipi- 
tate may  form  in  the  bath,  but  this  should  only  be  slight, 
otherwise  it  is  caused  by  incorrect  mixing,  the  action  of 
light,  or  by  contact  with  a metallic  surface. 


Positive  Motion  Picture  Film 


23 


Tone  C 

Tone  C — Red  Brown  (Uranium) 

I Positive  Employed — Medium 

The  toning  formula  employed  and  the  instructions  to  be 
followed  are  the  same  as  for  Tone  B,  the  time  of  toning 
being  about  5 minutes  at  65  degrees  to  70  degrees  F. 

Tone  D 

Tone  D — Brown  (Uranium) 

Positive  Employed — Normal 

The  toning  formula  employed  and  the  instructions  to  be 
followed  are  the  same  as  for  Tone  B,  the  time  of  toning 
being  about  3 minutes  at  65  degrees  to  70  degrees  F. 

Tone  E 

Tone  E — Sepia  (Uranium  and  Iron) 

This  particular  tone  is  obtained  by  suitable  mixture  of 
red  and  blue  toning  solutions.  By  varying  the  proportions 
of  these  baths,  tones  varying  from  red  to  sepia  may  be 
obtained. 

The  following  is  only  one  of  the  many  tones  produced  by 
this  method.  Increase  in  the  proportion  of  the  iron  bath 
makes  the  tone  colder,  and  vice  versa. 

Positive  Employed — Medium 

Immerse  the  well  washed  film  in 

Solution  for  tone  B (red  brown)  5 vols. 

Solution  for  tone  H (blue)  1 vol. 

Time  of  Toning  3 to  4 minutes  at  65  degrees  to  70  degrees  F. 

The  instructions  regarding  method  of  procedure,  life  of 
bath,  etc.,  are  exactly  the  same  as  for  tone  B. 

Tone  F 

Tone  F (Sulphide) 

Positive  Employed 

With  a thin  positive  a warm  brown  tone  is  obtained, 
while  with  denser  film  the  effect  is  that  of  a blue-black  tone. 


A. 

Potassium  Ferricyanide 

Avoirdupois 
8 lbs.  5 ozs. 

Metric 
4000  grams 

Potassium  Bromide 

2 lbs.  2 ozs. 

1000  grams 

Water  to 

50  gals. 

200  liters 

B. 

Sodium  Sulphide  (crystal) 

2 lbs.  2 ozs. 

1000  grams 

Water  to 

50  gals. 

200  liters 

24 


Tinting  and  Toning  of  Eastman 


A trace  of  iron  in  the  sodium  sulphide  will  do  no  harm 
providing  the  solution  is  boiled  and  the  precipitated  iron 
sulphide  allowed  to  settle  before  use.  The  well  washed 
positive,  is  thoroughly  bleached  in  A,  washed  for  5 minutes, 
and  immersed  in  solution  B until  the  film  is  thoroughly  toned. 
Temperature  of  Toning — 65  degrees  to  70  degrees  F. 

Time  of  Toning — Four  to  five  minutes. 

Time  of  Washing — Ten  to  fifteen  minutes. 

Life  of  Baths 

The  toning  baths  A and  B are  comparatively  stable  and 
will  keep  until  exhausted. 


Tone  G 


Tone  G — Olive  Green  (Iron) 

Positive  Employed — Thin  to  medium. 

The  best  tones  are  only  obtainable  on  film  developed  in 
an  Elon-Hydrochinon  developer.  Thoroughly  bleach  the 
well  washed  film  in  : 

Avoirdupois  Metric 

A.  Potassium  Ferricyanide  20  lbs.  12  ozs.  10,000  grams 
Ammonia  (concentrated 

.89)  K gal.  2 liters 

Water  to  50  gals.  200  liters 


Time  of  Bleaching — Two  to  five  minutes. 

After  washing  for  10  to  15  minutes,  tone  in  the  following 
at  65  degrees  to  70  degrees  F. : 


B.  Ferric  Alum  (Ferric  Am- 
monium Sulphate) 
Potassium  Bromide 
Hydrochloric  Acid  (con- 
centrated) 

Water  to 


Avoirdupois 

4 lbs.  2 ozs. 
2 lbs.  2 ozs. 

13  ozs. 

50  gals. 


Metric 

2000  grams 
1000  grams 

400  cc. 

200  liters 


Time  of  Toning 

Toning  should  be  complete  in  from  3 to  5 minutes. 
Time  of  Washing — Ten  to  fifteen  minutes. 

If  the  highlights  are  stained  blue,  or  if  the  image  will  not 
completely  tone  in  the  shadows,  this  is  due  to  insufficient 
washing  after  bleaching.  When  bleaching,  it  is  important 
to  examine  the  film  as  little  as  possible,  otherwise  streaks 
are  liable  to  be  produced  due  to  the  action  of  the  air  at  those 
parts  where  the  solution  drains  off  the  film.  It  is  also  im- 
portant to  tone  immediately  after  bleaching  and  washing. 


Positive  Motion  Picture  Film 


25 


Life  of  Baths 
Bleach  A. 

Providing  the  solution  is  screened  from  the  light  and 
kept  covered  to  prevent  the  undue  escape  of  ammonia,  the 
bath  keeps  fairly  well,  but  if  it  shows  any  signs  of  weaken- 
ing, it  should  be  revived  by  the  addition  of  a further  quantity 
of  ammonia  equal  in  amount  to  that  originally  used.  If  so 
revived  at  intervals,  50  gallons  will  bleach  40,000  feet  of 
film  before  exhaustion. 


Solution  B. 

Fifty  gallons  of  solution  B will  tone  30,000  feet  of  film 
without  further  addition  of  acid,  when  it  should  be  thrown 
away. 

Tone  H 

Tone  H Blue  (Iron) 

Positive  Employed  Thin  or  Medium,  according  to  result 
desired. 


Tone  in  the  following: 

Potassium  Bichromate 
Ferric  Alum  (Ferric  am- 
monium sulphate) 
Oxalic  Acid 
Potassium  Ferricyanide 
Ammonium  Alum 
Hydrochloric  Acid  10% 
Water  to 


Avoirdupois  Metric 

75  grains  5 grams 


8 ozs.  85  grs. 

1 lb.  4 ozs. 
6^4  ozs. 

2 lbs.  2 ozs. 
6J4  ozs. 

50  gals. 


250  grams 
600  grams 
200  grams 
1000  grams 
200  cc. 

200  liters 


The  method  of  compounding  this  bath  is  very  important. 
Each  of  the  solid  chemicals  should  be  dissolved  separately 
in  a small  quantity  of  warm  water,  the  solutions  allowed  to 
cool,  filtered  into  the  tank  strictly  in  the  order  given,  and 
the  whole  diluted  to  the  required  volume.  If  these  instruc- 
tions are  followed,  the  bath  will  be  a pale  yellow  color, 
perfectly  clear,  and  will  remain  so  for  a considerable  period. 
Time  of  Toning — Five  to  ten  minutes  at  70  degrees  F. 
Time  of  Washing 

Wash  for  ten  to  fifteen  minutes  until  the  highlights  are 
clear.  A very  slight  permanent  yellow  coloration  of  the 
clear  gelatine  will  usually  occur,  but  should  be  only  just 
perceptible,  when  it  will  have  no  effect  on  projection.  If  the 
highlights  are  stained  blue,  then  either  the  film  was  fogged 
during  development  or  the  bath  was  not  compounded  cor- 
rectly. Washing  should  not  be  carried  out  for  too  long  a 


26 


Tinting  and  Toning  of  Eastman 


period,  especially  with  water  inclined  to  be  alkaline,  because 
the  toned  image  is  soluble  in  alkali. 

Life  of  Bath 

If  the  acid  is  renewed  to  the  extent  of  the  original  amount 
after  toning  each  5000  feet,  the  bath  is  capable  of  toning 
15,000  feet  per  50  gallons  of  solution. 

If  even  after  revival,  the  tone  remains  flat,  the  bath  is 
exhausted  and  should  be  thrown  away. 

After  continued  use,  a slight  bluish  sludge  will  collect 
in  the  bath,  but  this  is  not  harmful.  Should  this  form, 
however,  to  any  appreciable  extent,  it  is  due  either  to  incor- 
rect mixing,  the  action  of  light,  or  to  contact  with  metallic 
surfaces. 

Tone  I 

Tone  I — Pale  Blue  (Iron) 

The  instructions  are  as  for  Tone  H with  the  following 
modifications : 

Positive  Employed — Normal. 

Time  of  Toning — Two  to  four  minutes  according  to  depth 
of  tone  desired. 


New  Tones 


Tone  J 

Tone  J — Red  (Dye  Tone) 

By  first  toning  in  Tone  A,  washing,  and  then  immersing 
the  copper  toned  film  in  an  acid  solution  of  a basic  dye,  the 
dye  is  mordanted  to  the  toned  image,  thus  modifying  the 
color. 


Nature  of  Positive — Medium 


Tone  for  five  to  ten  minutes  in  solution  as  for  Tone  A, 


and  after  washing  for  ten  minutes  immerse  in  the  following 
dye-bath. 

Avoirdupois  Metric 

Safranine  A (National 
Aniline  and  Chemical 


Co.,  Inc.)  7 ozs. 

Acetic  Acid  (Glacial)  32  ozs. 

Water  to  50  gals. 


200  grams 
1000  cc. 

200  liters 


Positive  Motion  Picture  Film 


27 


Time  of  Toning 

Five  to  ten  minutes,  according  to  depth  desired. 
Temperature  of  Toning — 65  degrees  to  70  degrees  F. 

Time  of  Washing 

Usually  only  a slight  rinse  in  water  is  necessary  If 
the  highlights  are  stained,  the  film  should  be  washed  for  five 
or  ten  minutes  or  until  clear.  Stained  highlights  are  caused 
either  by  insufficient  washing  after  toning,  too  strong  a dye- 
bath,  or  an  incorrect  amount  of  acid  in  the  dye-bath. 


Tone  K 


Tone  K — Orange  (Dye  Tone) 


The  instructions  are  exactly  as  for  Tone  J,  substituting 
the  following  dye-bath. 


Chrysoidin  3R  (National 
Aniline  and  Chemical 
Co.,  Inc.) 

or  Chrysoidin  Y (Extra) 
Acetic  Acid  (Glacial) 
Water  to 


Avoirdupois  Metric 


2 ozs.  320  grs.  80  grams 
32  ozs.  1000  cc. 

50  gals.  200  liters 


Tone  L 

Tone  L — Violet  (Dye  Tone) 

The  instructions  are  exactly  as  for  Tone  J,  substituting 
the  following  dye-bath : 

Avoirdupois  Metric 

Methyl  Violet  (National 
Aniline  and  Chemical 

Co.,  Inc.)  2 ozs.  320  grs.  80  grams 

Acetic  Acid  (Glacial)  32  ozs.  1000  cc. 

Water  to  50  gals.  200  liters 

Intermediate  Dye  Tones 

The  depth  of  the  dye  tone  is  determined  by  the  time  of 
immersion  both  in  the  copper  toning  bath  and  in  the  dye- 
bath.  Pale  tones  may  therefore  be  obtained  either  by  giving 
a short  bath  in  Tone  A and  fully  dyeing,  or  by  toning  for 
a longer  time  and  giving  a short  immersion  in  the  dye-bath. 

By  mixing  the  dye-baths  J,  K,  and  L in  varying  propor- 
tions intermediate  colors  may  be  obtained  just  as  in  tinting. 


28 


Tinting  and  Toning  of  Eastman 


Tone  M 

Tone  M — Pale  Red  (Dye  Tone) 

Positive  Employed — Normal 

Tone  for  one  to  two  minutes  in  Tone  A,  wash  for  ten 
minutes  and  then  immerse  in  the  following  dye-bath. 

Dye  solution  for  Tone  J,  one  volume. 

Dye  solution  for  Tone  K,  one  volume. 

When  the  desired  tone  is  obtained  rinse  until  the  high- 
lights are  clear. 


Compound  Tones 


Tone  N 

Tone  N — Copper-Iron-Dye  Tone. 

By  first  partially  toning  the  black  and  white  film 
(Medium)  in  Tone  A for  three  to  four  minutes  at  65  degrees 
to  70  degrees  F.,  so  that  the  half-tones  are  completely  toned 
but  the  shadows  only  partially,  washing  for  ten  minutes 
and  then  completing  the  toning  process  in  the  blue  toning 
bath  H,  the  residual  silver  in  the  shadows  is  toned  blue. 
In  this  way  a double  tone  is  obtained,  the  shadows  appearing 
dark  blue  and  the  half-tones  reddish  brown. 

By  immersing  the  film  toned  in  this  manner  in  the 
Chrysoidin  dye-bath  as  given  under  Tone  K,  the  dye  is 
mordanted  to  the  half-tones  which  contain  copper  ferro- 
cyanide,  producing  the  effect  indicated. 

Combined  Tinting  and  Toning 

In  many  cases  pleasing  effects  may  be  obtained  by  tinting 
film  which  has  already  been  toned,  the  result  being  that  the 
clear  portions  or  highlights  assume  the  color  of  the  dye, 
while  the  shadows  and  half-tones  project  a tint  intermediate 
between  that  of  the  dye  and  the  toned  deposit. 

Considerable  judgment  is  necessary,  however,  in  choos- 
ing suitable  tints  to  blend  with  any  given  tone. 

The  most  successful  combination  of  toning  with  tinting 
is  in  the  production  of  sunset  and  moonlight  effects  over 
water,  by  first  toning  blue  and  then  tinting  orange,  red  or 
yellow. 


Positive  Motion  Picture  Film 


29 


The  following  combinations  will  cover  most  cases  re- 
quired : 

Tones  A,  B,  C,  D,  E,  F,  J,  K,  L.  Tints  Nos.  2,  5,  6. 

Tones  G,  H,  I.  Tint  almost  any  delicate  shade. 

It  is  considered  unnecessary  to  illustrate  every  combina- 
tion of  tone  and  tint  above,  so  that  only  typical  examples 
are  given.  It  must  be  noted  that  toned  film  (except  tones 
A and  F)  absorbs  the  dye  more  quickly  than  untoned  film, 
so  in  order  to  duplicate  appended  samples,  the  dye-baths 
should  be  diluted  accordingly. 

Very  pleasing  effects  may  also  be  obtained  by  locally 
tinting  toned  film,  the  color  being  applied  either  by  hand 
with  a brush,  or  by  stencilling. 

Equipment 

The  equipment  necessary  for  systematic  tinting  and 
toning  is  essentially  the  same  as  that  required  for  develop- 
ment, consisting  of  the  usual  tanks  and  racks  or  small 
drums,  only  it  is  advisable  that  they  should  be  used  for 
this  purpose  exclusively  and,  if  possible,  occupy  a separate 
room  to  exclude  any  possibility  of  contaminating  the  devel- 
oping solutions  by  the  copper  or  sulphiding  bath,  which 
would  cause  development  fog  immediately. 

The  “drum”  system,  on  account  of  the  expense  involved 
in  apparatus  and  the  larger  space  required  for  manipulation, 
is  not  to  be  recommended  for  tinting  and  toning  operations, 
though  for  operation  on  a small  scale,  a small  wooden  drum 
revolving  in  a shallow  wooden  tank  is  most  efficient  and 
economical. 

When  the  tank  and  rack  system  is  employed,  the  tanks 
shoud  be  of  slate  or  other  resistive  material,  and  have  an 
outlet  at  the  bottom  in  the  form  of  a hard-rubber  stopcock 
or  a plain  wooden  plug.  The  racks  or  drums  may  be  of 
wood,  but  if  metal  pegs  are  employed  on  the  racks  they 
should  be  coated  with  acid-resisting  paint  such  as  asphalt, 
since  the  presence  of  any  metallic  surface  in  the  toning  baths 
will  cause  contamination  and  effect  a precipitation  of  sludge. 
The  frames  should  not  be  interchanged  but  kept  separate 
either  for  tinting  or  toning  to  prevent  contamination  of  one 
bath  with  racks  previously  employed  in  another.  This  also 
applies  to  the  small  drum  system.  For  instance,  a pink  tint 
would  be  ruined  by  using  a rack  which  had  previously  been 
immersed  in  a deep  blue  dye-bath,  unless  that  particular 


30 


Tinting  and  Toning  of  Eastman 


rack  had  been  thoroughly  washed.  In  the  case  of  delicate 
tinting,  however,  no  harm  is  done  providing  the  racks 
have  been  previously  coated  with  the  following  waterproof 
varnish : 

Avoirdupois  Metric 

Hard  paraffin  3^4  lbs.  1600  grams 

Carbon  tetrachloride  10  gals.  40  liters 

Before  treatment  it  is  preferable  to  immerse  the  racks 
which  have  been  previously  used  for  developing,  in  a 1% 
solution  of  hydrochloric  acid  for  two  or  three  minutes,  wash 
for  fifteen  minutes  and  thoroughly  dry.  The  well-dried 
racks  are  then  dipped  in  the  above  solution  and  the  excess 
liquid  drained  off,  when  the  varnish  dries  almost  immediate- 
ly. The  varnishing  should  be  repeated  at  intervals. 

Mixing  Solutions 

Developers,  toning  solutions  and  dyes  should  be  mixed 
in  crocks  of  glazed  earthenware  or  enameled  iron,  using 
warm  water  where  necessary  and  ensuring  thorough  solution 
by  stirring  with  a wooden  paddle,  which  should  be  thor- 
oughly washed  after  each  operation.  Having  thus  dissolved 
the  chemicals  in  as  small  a quantity  of  warm  water  as 
possible,  filter  through  fine  muslin  and  make  up  the  bath 
with  cold  water,  so  that  the  final  solution  will  be  at  approxi- 
mately the  correct  temperature. 

The  chemicals  employed  should  be  pure  ( for  the  samples, 
“EKCo.”  tested  chemicals  were  used),  and  in  cases  where  a 
good  water  supply  is  not  available,  only  distilled  water 
should  be  used. 

Troubles  in  Toning 

Most  difficulties  met  with  in  toning  may  be  traced  to  one 
or  more  of  the  following  causes: 

Uneven  Toning 

This  may  be  due  to : 

a.  Grease  on  the  film.  Never  project  film  before  tinting 
or  toning. 

b.  Drying  spots  on  untoned  film.  If  possible,  always 
tint  or  tone  film  immediately  after  washing  and  before 
drying. 

c.  Examination  of  the  film  too  frequently  during  toning, 
causes  an  oxidation  of  the  toning  solution  in  places  where 
the  solution  fails  to  drain  from  the  film. 


Positive  Motion  Picture  Film 


31 


d.  Insufficient  or  uneven  washing  of  the  film  after 
bleaching  and  before  toning  (Tones  F and  G). 

White  Spots 

White  spots  are  produced  by  particles  of  hypo  or  car- 
bonate dust  or  splashes  of  a solution  of  these,  settling  on 
the  toned  film.  The  toned  image  consists  of  silver  together 
with  more  or  less  silver  ferrocyanide  and  the  ferrocyanides 
of  uranium,  iron  and  copper  as  the  case  may  be.  Silver 
ferrocyanide  is  soluble  in  hypo  while  uranium  and  iron 
ferrocyanides  are  soluble  in  a solution  of  sodium  carbonate, 
strong  ammonia,  etc.,  so  that  the  white  spots  indicate  those 
parts  where  the  toned  image  has  been  dissolved  away. 

Irregular  white  spots  may  also  be  formed  if  the  film  is 
imperfectly  squeegeed  after  washing  and  before  drying, 
especially  if  the  wash  water  is  slightly  alkaline.  When  a 
spot  of  water  on  the  toned  film  evaporates,  the  small  amount 
of  alkali  present  in  the  water  becomes  more  concentrated 
and  finally  dissolves  away  more  or  less  of  the  tone,  leaving 
a white  spot  on  the  film. 

White  spots  due  to  these  causes  may  be  prevented  by 
immersing  the  film  for  a few  seconds  in  a .5%  solution  of 
glacial  acetic  acid  after  toning  and  before  placing  on  the 
drying  rack. 

Stained  Highlights 

Are  caused  by : 

a.  Traces  of  fog  on  the  film  before  toning. 

b.  An  improperly  compounded  toning  bath.  All  solu- 
tions when  new  should  be  perfectly  clear. 

c.  Premature  exhaustion  of  the  bath.  This  is  due  either 
to  the  action  of  light  or  to  the  presence  of  some  metal  in  the 
tank  in  the  shape  of  screw  heads,  faucets,  pins,  etc.,  which 
gather  the  tone  and  cause  the  formation  of  sludge. 

It  is  important  to  keep  all  solutions  containing  potassium 
ferricyanide  exposed  as  little  as  possible  to  daylight,  to  use 
only  wooden  racks  with  wooden  pegs,  and  to  cover  all  metal 
parts  very  carefully  with  acid  resisting  paint. 

d.  In  dye-toning,  stained  highlights  are  due  either  to 
insufficient  washing  after  toning  with  copper,  too  strong  a 
dye-bath,  or  an  incorrect  amount  of  acid  in  the  dye-bath. 


Tints 


Tones 


■r  - 

# •* , 


Tinted  and  Toned 


J 


Tone  C 
Tint  1 


Tint  4 


L Tone  C 

Tint  6 


Tone  H 
Tint  2 


Tone  J Tone  H 

Tint  6 Tint  8 


